ACPAtmospheric Chemistry and PhysicsACPAtmos. Chem. Phys.1680-7324Copernicus PublicationsGöttingen, Germany10.5194/acp-11-10487-2011An important fingerprint of wildfires on the European aerosol loadBarnabaF.1AngeliniF.1CurciG.2GobbiG. P.11Istituto di Scienze dell'Atmosfera e del Clima, Consiglio Nazionale delle Ricerche (ISAC-CNR), Roma, Italy2CETEMPS-Dipartimento di Fisica, Università degli Studi dell'Aquila, L'Aquila, Italy2410201111201048710501This work is licensed under a Creative Commons Attribution 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0/This article is available from http://www.atmos-chem-phys.net/11/10487/2011/acp-11-10487-2011.htmlThe full text article is available as a PDF file from http://www.atmos-chem-phys.net/11/10487/2011/acp-11-10487-2011.pdf

Wildland fires represent the major source of fine aerosols, i.e.,
atmospheric particles with diameters <1 μm. The largest numbers of
these fires occur in Africa, Asia and South America, but a not negligible
fraction also occurs in Eastern Europe and former USSR countries,
particularly in the Russian Federation, Ukraine and Kazakhstan. Besides the
impact of large forest fires, recent studies also highlighted the crucial
role played by routine agricultural fires in Eastern Europe and Russia on
the Arctic atmosphere. An evaluation of the impact of these fires over
Europe is currently not available. The assessment of the relative
contribution of fires to the European aerosol burden is hampered by the
complex mixing of natural and anthropogenic particle types across the
continent. In this study we use long term (2002–2007) satellite-based fires
and aerosol data coupled to atmospheric trajectory modelling in the attempt
to estimate the wildfires contribution to the European aerosol optical
thickness (AOT). Based on this dataset, we provide evidence that
fires-related aerosols play
a major role
in shaping the AOT yearly
cycle at the continental scale. In general, the regions most impacted by
wildfires emissions and/or transport are Eastern and Central Europe as well
as Scandinavia. Conversely, a minor impact is found in Western Europe and in
the Western Mediterranean. We estimate that in spring 5 to 35% of the
European fine fraction AOT (FFAOT) is attributable to wildland fires. The
estimated impact maximizes in April (20–35%) in Eastern and Central
Europe as well as in Scandinavia and in the Central Mediterranean. An
important contribution of wildfires to the FFAOT is also found in summer
over most of the continent, particularly in August over Eastern Europe
(28%) and the Mediterranean regions, from Turkey (34%) to the Western
Mediterranean (25%). Although preliminary, our results suggest that this
fires-related, continent-wide haze plays a not negligible role on the
European radiation budget, and possibly, on the European air quality,
therefore representing a clear target for mitigation.